1. Field of Invention
The present invention relates to an optoelectronic package, and more particularly, to an optoelectronic package with a wire-protection lid.
2. Related Art
Conventional optic components are manufactured on a semiconductor wafer in bulk, and an optoelectronic package process is carried out after the wafer is cut into dies. Since bonding wires are generally used to electrically connect the dies to the substrate in the conventional optoelectronic package process, appropriate protection of the bonding wires is required. Recently, a method for protecting the bonding wire of an optoelectronic package is to protect the bonding wires by sealing them with a molding compound formed by molding.
Referring to FIG. 1, a conventional optoelectronic package 1 mainly includes a substrate 10, a silicon die 20, a glass 30, a plurality of bonding wires 40, and a molding compound 50. The silicon die 20 has an active surface 21 with a plurality of optical elements, e.g., micro-mirror structures, formed in its light working area 22, and a plurality of pads 23 are disposed at the edge of the active surface 21. Further, the glass 30 is fixed on the active surface 21 of the silicon die 20 through an annular block 60, for protecting the light working area 22. After the silicon die 20 is disposed on a top surface 11 of the substrate 10, the bonding wires 40 are formed by wiring to electrically connect the pads 23 of the silicon die 20 and the substrate 10. The molding compound 50 is formed by molding, to protect the bonding wires 40 by sealing them. However, the wire collapse and short circuit easily occur to the bonding wires 40 due to the molding pressure of the molding compound 50. Moreover, the molding compound 50 may overflow to the glass 30, or the light working area 22 of the silicon die 20 may be contaminated by the overflow of the molding compound 50, since the block 60 is broken due to the excessive molding pressure of the molding compound 50, such that the operation of the optical elements in the light working area 22 fails.
Another conventional method for protecting bonding wires of an optoelectronic package utilizes hermetically sealing, which is disclosed in, for example, U.S. Pat. No. 6,809,852, wherein a die is disposed on a substrate, and micro-mirror structures are disposed on a glass carrier (or referred as glass die) on the die, to form an optical cell. The die and the substrate are electrically connected with bonding wires. Further, a ring is disposed on the substrate, and a transparent lid made of e.g., glass is patched on the ring, to hermetically seal the bonding wires. However, such a bonding wire protection method cannot ensure the transparent lid to be parallel to the active surface of the die and the glass carrier, therefore, when the light or image passes through the transparent lid and the glass carrier, the risks of light refraction, scattering, and defocusing will be increased, thereby the quality of the optoelectronic package is deteriorated.